Barry, The car is looking great! Some vinyl should work just fine on the inlets. What is your weight at this point? Do you have steel doors, fenders etc?
I am also building a E46 M3 and have a hefty order into Bimmerworld..........about 2-3 months away from where you are at. We are sub 2500lb. stripped (All steel panels at this point) going to get the cage built in a few days.
Please post up some video/reviews once you get it on the track!